Hi.
I have a 4.3 v6 4x4 auto.
the problem I have is that it can run for 3 hours non stop and not lose a drop of coolant, but when its switched off, it starts to leak, not straight away, but after about 10 mins or so. leaks from the radiator area. the hoses seem fine, the ones I can see at least.


I recently changed the thermostat due to being stuck open causing it to run cool and had air in the system. but both of those are now cured and this new problem has started.


any ideas?

 

check the rad hoses and the water pump should find the leak quite easily

 

the water pump is dry, nothing seems to be coming from there.
its definitely the radiator area. the hoses themselves are on tight.


im going to get some K-seal, and put that in the system. been told that's the best cooling system sealer on the market. not sure if you guys have heard of that in the usa. has ceramic particles in it to bond to any holes etc.


I understand that when these engines are turned off, the temp goes up a bit, causing extra pressure in the system, hence it doesn't leak at all when the engine is running. hoping this will at least slow it down,better still,stop it until im in a position to get a new radiator. its a real pain getting one to the uk.
but in the mean time, any other possible causes or locations?

 

I had a radiator leaking on mine about two years ago. I was going through about a gallon of water every two or three days. It was on the drivers side of the radiator, at the crimp where the side tank is attached.

I'm not a fan at all of any "miracle in a can" engine sealers. I've never heard of the one you mention, my experience is that stuff gets all through the engine, and into places you don't want.

If it's going to be soon that you get a radiator, just keep adding water to it. Straight water isn't the best to use, normally, because of rust, lower boiling point than anti-freeze, etc. But it gets expensive if you are having to add a ton of coolant every few days.

 

I wouldn't put the miracle cure stop leak in anything of mine ever. The stuff may help stop the leak but it is a temporary fix and it can also help clog up other areas that are not leaking and stop your lines in the block. Everyone has there own preference but i would rather spend more now to get it fixed than alot later to fix the after effects of it.

 

well, the so called 'sealer' was a load of rubbish. but worth a shot.
so now im trying to find a replacement radiator.
trouble is, I have looked at rockauto website, and they only seem to stock the rads for the usa market. the uk models have the outlets on opposite sides, the recovery and rad cap are on the other side. as you face the engine bay from the front of the car, the lower hose is on the right side of the rad ( that goes to the oil cooler under the rad ), the rad cap and recovery tank also on the right. the left side of the rad has the upper hose, that leads to the thermostat.
I am having trouble locating a radiator of this configuration. any ideas?
also is the oil cooler attached to the underside of the rad or something else, as I cant tell, and wont be taking it apart till im able to complete the job, as the vehicle is used daily.
thanks

 

I found a new radiator on Amazon.com at a decent price. Fair warning however, apparently some radiators come with a moulded piece that looks like the drain plug for the bottom of the rad. However, it isn't open. You might think your existing drain plug would fit in it but it likely won't. In short, if you have to drain it in the future, do it through the hoses.

Don't know if you're aware of the mixing of Dexcool and regular anti-freeze as well. Not knowing this ultimately led to a blown head gasket for me. The long and short, if you or the previous owner did the Dexcool/anti-freeze mix, chances are very high that your intake and possibly head gaskets are deteriorating, among other items (heater core, radiator, etc.).

All I am really saying, is don't be terribly surprised about new issues requiring lots of time and effort no matter what your fix is. The silver lining is that they are not impossible to handle. Those 4.3s are great engines and I think worth the time and effort.